Coordination of benefits (COB)
Coordination of benefits (COB) is a provision in most health insurance plans. This provision provides the order in which plans pay claims. It is designed to avoid duplication of coverage and payments.
A COB is necessary when an individual is covered under more than one health plan. Typically, the primary plan pays first and the secondary plan pays after. However, some plans allow the secondary plan to also cover additional benefits. The secondary plan may pay some of the cost, but this may be limited to 100% of the eligible charges.
Health plans can be group or nongroup. Group plans are self-insured or fully insured. Some groups are also covered by Medicaid.